Improvement in piston-rod packings



J. HEWITT. Piston-Rod Packing.

No. 216,038. Patented June 3,1879.

Ti g.1.

P cm W Att est. q

"PEIERS, PHOTO-LITHQGRAPHER, WASHKNGTON. 0 c

UNITED STATES PATENT QFFIGE.

JOHN HEWITT, OF ST. LOUIS, MISSOURI.

IMPROVEMENT IN PlSTON-ROD PACKIN GS.

Specification forming partof Letters Patent No. 216,038, dated J one 3 1879; application filed March 14, 1879.

annexed drawings, making part of this specification, in which Figure 1 is a longitudinal section taken through a stuffing-box having the improve 'ment, and showing the packing and gland partly in section and partly in elevation and the rod in elevation Fig. 2, a section taken through the gland on the line a0 a, Fig. 1 Figs. 3 and'4, a side elevation and a crosssection, respectively, of one of the set of packing-rings that bear upon the stufling-box; and Figs. '5 and 6, a cross-section and a side elevation, re spectively, of one of the rings that bear upon the rod.,

The same letters denote the same parts.

The present invention relates partly to the character of the material of which the packing is composed and partly to the shape in which the material is used. It also has referalso beveled. The effect of this is, that as the gland is forced into the stuffingbox the packing is wedged against the surfaces intended to be packed.

The packing should be of such material as will enable it to be moved as a mass by the gland, and at the same time it should be sufficiently malleable or moldable to enable it, un-

der the pressure of the gland, to become accurately shaped to the surface that it is'intended. to pack, and so that each section or part of the packing shall become accurately fitted to the contiguous sections or parts.

- The'most effective and desirable substance I have found by trial to be lead or an alloy of lead and some metal that slightly hardens the lead and the invention is most effectively carried out, as shown in the accompanying drawings, where-- A represents a stuffin g-box of the usual form, and B the gland, which also is of the customary shape, saving that its inner edge, b, that comes against the packing, is beveled, and that the gland is provided with chambers 72 I), for the purpose hereinafter described.

0 represents the packing. It is in the form of a series of rings, 0 c c c c 0 which, in cross-section, are triangular, and which are arranged as sl1own-that is, the rings 0 c c with the base 0 toward the rod D, and the alternate ones, c 0 0 with the base toward the surface a of the box. Thus arranged, the efi'ect is that when the gland, by means of thebolts 1) 11 is forced against the packing the rings 0 c c are contracted upon the rod, and the rings 0 c c are expanded against the surface a of the stuffing-box,- each one of the rings, under the action of the gland, serving as a wedge to force the adjacent rings against the rod and box. This causes the bases 0 to be closed against the rod and boxto any desired degree of tightness, and, owing to the nature of the material of which the rings are formed, the bases of the rings become perfectly fitted to the rod and the surface a, and those joints in consequence are perfectly packed. The various rings 00 c c c 0 also become so thoroughly compacted and fitted together as to prevent the passage-of steam between them.

so far as packing the joint between the pack ing and the rod is concerned a single ring, 0, in combination with the beveled gland, suffices but to pack the joint between the pack ing and the surface a of the stuffing-box at least two rings, 0 c, are needed. It is also better tov employ a series, 0 c c c 0" 0 as shown, as thereby. it becomes practicable to extendthe bearing-surface of the packing and to render it more reliable. The last ring, 0

may be of a less compressible material than that of the other rings, or this part 0 may be made in one piece with the box A, the object, so far as this part of the construction is concerned, being mainly to obtain a beveled surface, c for the ring 0 to come against.

In using metallic packing the piston-rod sometimes needs lubricating. Accordingly,

the gland is preferably provided with the chambers b b, one or more, as desired, in which waste and oil can be held, and the rod thereby lubricated. The openings to these chambers are at I) b. V

The improvement as described is as in connection with the piston-rod and stuffing-box of a steam-engine cylinder. 'It is equally adaptable, however, to the plunger of a pump or to the packing of a joint between two pipes.

I claiml. The box A, having the surface a, the gland B, having the beveled edge I), the rings 0 0 0", shaped as described, and formed of lead or JOHN HEWITT.

Witnesses HERMAN GUELS, OHAs. D. MoonY. 

